Approximately half of adolescent mothers in the U.S. begin parenting having experienced at least one serious childhood risk factor for poor psychosocial development including maltreatment and foster care placement. These risk factors contribute to multiple problem behaviors including conduct problems and substance abuse among these adolescent mothers at risk (AMARs). A robust body of research indicates that difficulties in regulating emotions are associated with childhood risk factors and underlie later behavior problems. Emotional regulation (ER) problems severely compromise AMARs' abilities to engage in sensitive and responsive parenting. However, there are currently no rigorously tested, efficacious, sustainable behavioral interventions targeted for AMARs, and no interventions have yet focused on the interplay of AMARs' problem behaviors, effective parenting, and ER problems. Our research team has begun to develop a multi-component, technology-enhanced, and developmentally appropriate prevention intervention (Power Source Parenting [PSP]). The primary goal of PSP is to foster autonomous and adaptive ER functioning to promote sensitive, non-abusive parenting and the reduction of behaviors, including substance use, that place AMARs and their offspring at risk. The PSP intervention builds on evidence-based practices for increasing positive parenting and includes innovative mobile technology components: PSP trains AMARs in mindfulness meditation and social cognitive skills in group sessions and integrates a state-of-the-art biosensor wrist band and smart phone application to assist AMARs to use these skills in vivo. The biosensor band communicates physiological states wirelessly to a smart phone sending individually tailored intervention material (text, voice images) at the moment of emotional arousal. We have piloted and explored the feasibility and acceptability of the PSP intervention components with AMARs. The proposed study builds on this promising formative work to accomplish the following aims in this R34 application: (1) refine the components of the PSP intervention and further examine their acceptability, safety, feasibility, and gather preliminary evidence of their efficacy with respect to the study's primary outcomes: (a) increasing positive parenting attitudes, skills, and knowledge; and (b) decreasing maternal risk behaviors (e.g., substance use, delinquency); (2) explore the putative mediator of the intervention: emotional regulation skills; and (3) explore preliminary evidence of efficacy on a secondary outcome, increasing adaptive relational skills for the development of one or more supportive relationships, a vital aspect of effective parenting. To accomplish these aims, we will conduct an exploratory, group randomized controlled trial with AMARs (12 group homes, N=80 AMAR). The study has high potential significance because it addresses critical public health problems including substance abuse, conduct problems, and child maltreatment, and the intergenerational transmission of these problem behaviors.